Add Vector interface
Add Path interface
Add Bezier path
Add PathTest
Add dragging
Add BSpline (only cubic for now).
Remove usage of Vector#tmp() in Bezier and BSpline
Add better visual test
Remove PathTest from the tests.
Replace CatmullRomSpline, reuse SplineTest by renaming PathTest to SplineTest.
Revert SplineTest to PathTest.
Revert CatmullRomSpline
Merge branch 'master' of https://github.com/libgdx/libgdx into misc
Update GdxTests to use PathTest
Remove SplineTest and CatmullRomSpline, rename CatmullRom to CatmullRomSpline.
Add the ability to test whether the canvas context is current. This is mainly useful for cases where you have multiple canvas contexts, and you want to know if any of them are current before loading a resource that requires an active context.
Only allow one drag action at a time

The DragAndDrop class only manages one payload and drag actor, so we
need to stop several drag events from happening at the same time.
Cleanup of DragAndDrop simultaneous drag patch

Fixes issues pointed out by @bitiotic
added Ellipse
Merge pull request #249 from viridia/master

Add isCurrent() method to LwjglAWTCanvas.